Disk bit



March 15, 1927.

W. S. HOLDAWAY DISK BIT Filed April 6, 1925 ell) and increasing the danger that t bit embodying the invention.

WILLIAM S. HQLDAWzhY, h nos ANQELES, CALIFORNIA.

nrsn BIT.

a lication fileddpz'll e. lees. aerial Flo. sense.

This invention relates to rotary dish bits of the type employed in the rotary method of drilling oil Wel This invention is directed to improve-v ments in the type of rotary disk bits employing a plurality of disk cutters mounted upon :1 prong body, the prongs being generally referred to in the art as legs. The bits of this type have generally been found to be the most successful in the rotary method of drilling Wells. Such disk bits, however, have two major defects which has to a large ea:- tent hindered their most universal adoption in the drilling of Wells. The first of the ditii culties referred to is the tendency of the drilling action to wear away the bottom end of the legs during drilling operations combuilt up e pins or bushings or the like employed to support the disk cutters thereon will drop out of the legs and be lodged in the well hole. The second dificulty referred to is the tendency of the legs of the prong of the body to break away from the body which with the present form of rotary drilling bits generellyecauses the entire disk bit to be thrown away...

An object of the present invention is to provide a disk bitconstructed with a detachable from the body so that it may be made of diflerent material than the remainder of the body, and thus materially stren then Without increasing greatly total cost of the disk bit and also furnishing a disk bit which upon the destruction oteits leg may have it repleced by a new and thus the entire bit saved from discrrd Another object ot the present in n is to rovide n disk bit with a mounti g ..nr the dies cutters which will permit lower ends of the legs to be materially Worn away without increasing the danger of ing removed from the bit.

Various further objects and pelling such legs to be repeatedly 1 the invention will be understood scription of preferred o y i.

pose reterence is to the are y, drawings wings: I

an elevntaon K dke broken away Fig. 3 is a section on the line33 of Fig. 1.

l is a section on the line l l of Fig. 15 an Fig. is a fragmentary view of the lower of the bit with detachable end of the body legs removed therefrom.

Referring to the drawings, the disc bit there illustrated comprises a body 2 having es an elongated shank 3 provided with an enlargement 4 near its upper end and termi noted in a; threaded pin 5 by.which the disk bit can be attached to a rotary string and rotated during drilling operations.

The shank 3 of the body is made of elon gated form in order that it through some ,accident the bit would become broken 0d from the strin and lodged in the Well hole it may be readily ipped by fishing tools and removed theret rbm. The lower end of the body 2 terminates in two spaced extensions or legs 6 and 7 which serve to mount disk cutters 8 and 9 respectively. The

spaced legs 6 and 7 are of duplicate construction and therefore it is necessary only to describe the construction of one, both of the legs being preferably made detachable from the body 2.

The legs are preferably shaped to od-set the disk cutters 8 and 9 mounted thereby in order to bring such disk cutters in advance of the drilling axis of the bit. It can be seen that upon pressing downward upon the drilling bit and rotating the same there will be a resulted stress applied upon the legs 6 and 7 in a direction angled from the longitudinel axis of the shank 2 of the body. In order to properly'hold the legs 6 or 7 to the body, it is therefore preferred to provide eontecting surfaces between the legs and shank 2 of the body angled to most properly receive this stems and insure theretaining of the legs thereto. For this purpose the lower end oi? the shank 2 is recessed ct its opposed sides as indicsted at 10 end ll, reaps-c thus providing upthrust bearing l2 and lit; respectively, for ends of the legs it and 'l respectively to upon the legs 6 and Z, andthereby v cutters end l the vertical or pressnre without teeuiring lend to be transmitted thereto d! utilized the innit.

its

downwardly and provided with trough like recesses 16 and 17, respectively, angled relative to the axis of the shank in the direction which the resulting stress upon the legs 6 and 7, respectively, will be imposed. The side walls of such sub-recesses are thus so formed that they act as bearing surfaces disposed to directly resist the stress applied upon the legs 6 and 7. The ends of the legs 6 and 7 are provided with surfaces shaped to fit the recesses 10 and 11 upon opposed sides of the shank, thus each leg is provided with a diagonally extending tongue 18 for fitting in sub-recesses 16 or 17 which are angled relative to the axis of the shank 2 of the body. I

Various means may be employed for clamping such legs and body together.

In the form of the invention shown there is employed two upper bolts 19 and 20 and two lower bolts 21 and 22 clamping the legs to the body in such manner that to themselves insure the legs being maintained rigid with the shank 2.

The usual form of mounting for the disk cutters on the legs is by passing a pin through an opening near the end of the legs and mounting the disk upon such pin either directly or upon bushings mounted thereon. With such construction the wearing away of the lower end of the legs will permit the pins to drop out leaving the disk cutters in the bottom of the well from which they must be fished out or ground up. The mounting herein provided eliminates largely this difficulty by providing inturned bosses 22 and 23 upon the legs 6 and 7, respectively, over which bushings 24 and 25 may be placed and locked thereto by suitable means,f:. su'ch as bolts 26 and 27, respectively, thus providing a mounting for the disk cutters.

With the form of rotary disk bit herein illustrated it is readily apparent that the legs 6 and 7 may be replaced as destroyed without compelling the purchase of an entirely new hit. Moreover, the legs.6 and 7 may be made of the highest grade of material to strengthen the disk-bit at its weakest point Without compelling the whole bit to be made of such highgrade material, thus providing increased strength in the bit without material increase in the cost. It should be pointed out that a large part of the material of the bit is disposed within the shank 3 which must be large and long in may readily be engaged by fishing tool. Hence the fact that the legs of the disk bit of this invention may be made of difl'erent material than the body is of great advantage in reducing the cost of the bit.

While the embodiment of the invention herein described is well suited for accomplishing the purpose of this invention, various modifications may be made in thedetails of construction of arrangement of parts without departing from the principles of the invention. The invention is not therefore limited to such construction details, but includes all such modifications and changes as come within the spirit of the appended claims:

1. A rotary disk bit comprising a body recessed at its lower end on opposedsides to form upthrust bearing faces and bearing faces angularly disposed, legs shaped to fit such recesses and engage such bearing faces, there being a tongue and groove connection between the legs and body, means clamping the legs to the shank, and disk cutters carried by and between the legs.

2. A rotary disk bit comprising the combination of a body recessed at its lower end on opposed sides to form upthrust bearing faces and bearing faces angularly disposed, legs shaped to fit said recessesand engaged by said bearing faces, the legs having a tongue and groove engagement with the body, the

tongue being angularly disposed, means for clamping the legs to said body, the legs being provided with integral bearing trunnions at their lower ends, and disk cutters carried by said trunnions.

3. A. replaceable leg for a disk bit comprising an integral trunnion on the lower order that hits broken off in the well hole part of the leg adapted tosupport a disk, the

leg at its upper end having an angularly disposed tongue. Signed at Los Angeles, California, this 30 day of March, 1925. v

WILLIAM S. HOLDAWAY. 

